<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>canvas练习</title>
</head>
<body>
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<script>
    function Demo() {

    }
    Demo.prototype = {
        a:function (b) {
            console.log(b);
        }
    }
    var demo = new Demo("a","jj");
//    var demo = new Demo[a]("xiuxi");
//    demo.a("xiushi");
//    demo[a]("xiushi");
</script>
</body>
</html>